Intermediates in the preparation of steriod 5-alpha-reductase inhibitors

ABSTRACT

Invented are 4-aza-5-alpha-8(14)-17 substituted-androsten-3-ones having an 8(14), 7(8), or 16(17) double bond, optionally also having a 1(2) double bond, pharmaceutical compositions containing the compounds, and methods of using these compounds to inhibit steroid 5-alpha-reductase.

This is a division of application Ser. No. 07/007,539 filed Jan. 28,1987, now U.S. Pat. No. 4,888,336.

FIELD OF THE INVENTION

The present invention relates to novel17-substituted-4-aza-5-alpha-17β-androsten-3-ones having an 8(14), 7(8),or 16(17) double bond, optionally also having a 1(2) double bond,pharmaceutical compositions containing these compounds, and methods forusing these compounds to inhibit mammalian steroid 5-alpha-reductase.

DESCRIPTION OF RELATED ART

The class of steroidal hormones known as androgens are responsible forthe physical characteristics that differentiate males from females. Ofthe several organs that produce androgens, the testes produce thesehormones in the greatest amounts. Centers in the brain exert primarycontrol over the level of androgen production. Numerous physicalmanifestations and disease states result when ineffective productioncontrol results in excessive androgen hormone production. For example,acne vulgaris, seborrhea, female hirsutism, and benign prostatichypertrophy are correlated with elevated androgen levels Additionally,the incidence of male pattern baldness has been associated with highandrogen levels.

Testosterone is the principal androgen secreted by the testes and is theprimary androgenic steroid in the plasma of males. It now is known that5-alpha-reduced androgens are the active hormones in some tissues suchas the prostate and sebaceous gland. Circulating testosterone thusserves as a prohormone for dihydrotestosterone (DHT), its5-alpha-reduced analogue in these tissues but not in others such asmuscle and testis. Steroid 5-alpha-reductase is a NADPH-dependent enzymethat converts testosterone to DHT. The importance of this enzyme in maledevelopment was dramatically underscored by discovery of a geneticsteroid 5-alpha-reductase deficiency in male pseudohermaphrodites.Imperato-McGinley, J., et al., (1979), J. Steroid Biochem. 5 11:637-648.

Recognition of the importance of elevated DHT levels in many diseasestates has simulated many efforts to synthesize inhibitors of thisenzyme. The structures of several known steroid 5-alpha-reductaseinhibitors are shown in Table 1.

                                      TABLE 1                                     __________________________________________________________________________    5-alpha-Reductase Inhibitors                                                  __________________________________________________________________________    (1)                                                                              ##STR1##              K.sub.1 = 1.1 × 10.sup.-6                                                         Hsia and Voight 1973                       (2)                                                                              ##STR2##              1 × 10.sup.-6 M (Irreversible)                                                    Robaire, et al., 1977                      (3)                                                                              ##STR3##              3.5 × 10.sup.-8 (Irreversible)                                                    Blohm, et al., 1980                        (4)                                                                              ##STR4##               5 × 10.sup.-9 M (Reversible)                                                     Liang, et al, 1983                         (5)                                                                              ##STR5##              1.25 × 10.sup.-6 M (Irreversible)                                                 Petrow, et al., 1981                       __________________________________________________________________________

The first inhibitor described was the 17-β-carboxylic acid (1) by Hsiaand Voight in 1973. J. Invest. Dermat. 62:224-227. The secosteroid (2)was the next inhibitor to be described and also has found utility as anaffinity label for 5-alpha-reductase. Robaire, B., et. al., (1977), J.Steroid Biochem. 8:307-310. The diazoketone (3) has been reported as apotent, time-dependent inhibitor of steroid 5-alpha-reductase. Blohm, T.R., et. al. (1980), Biochem. Biophys. Res. Comm. 95:273-280; U.S. Pat.No. 4,317,817, Mar. 2, 1982. Compound (4) is exemplary of a group of4-aza steroid inhibitors of steroid 5-alpha-reductase described in U.S.Pat. No. 4,377,584 which issued Mar. 22, 1983, and in Liang, T., et al.(1983), J. Steroid Biochem. 19, 385-390. The 6-methylene steroid (5)also has been shown to be a time-dependent inactivator of steroid5-alpha-reductase. Petrow, V., et. al. (1981), Steroids 38:121-140.

Other 5-alpha-reductase inhibitors also have been described. U.S. Pat.No. 4,361,578 which issued Jun. 2, 1986, describes a class ofhomosteroid enzyme inhibitors. Japanese Patents J60146855-A andJ60116657-A disclose various aniline derivatives having numerousactivities including 5-alpha-reductase inhibiting activity. JapanesePatent J60142941-A discloses phenyl-substituted ketones having5-alpha-reductase inhibiting activity and European Patent EP173516-Adiscloses various phenyl-substituted amides having similar activity.Shiseido referenced terpene derivatives that are active inhibitors ofsteroid 5-alpha-reductase. Japanese Patent No. J59053417-A.

SUMMARY OF THE INVENTION

The present invention resides in the discovery that steroid5-alpha-reductase is inhibited by4-aza-5-alpha-17-substituted-androsten-3-one compounds having an 8(14),7(8), or 16(17) double bond, optionally also having a 1(2) double bond.The compounds are potent enzyme inhibitors.

Presently preferred compounds of the invention and compounds used in theinvented pharmaceutical compositions and the invented methods include:

4-methyl-4-aza-5-alpha-8(14)-pregnen-3-one-(20R)-20-carboxylic acid,

(20R)-hydroxymethyl-4-methyl-4-aza-5-alpha-8(14)-pregnen-3-one, and

4-methyl-4-aza-5-alpha-8(14)-androsten-3-one-17β-N,N-diisopropylcarboxamide.

In a further aspect of the invention there are provided novelintermediates and novel processes useful in preparing the presentlyinvented 5-alpha-reductase inhibiting compounds.

The invention also is a method for inhibiting 5-alpha-reductase activityin mammals, including humans, that comprises administering internally toa subject in need thereof an effective amount of a presently invented5-alpha-reductase inhibiting compound.

Included in the present invention are pharmaceutical compositionscomprising a pharmaceutical carrier and compounds useful in the methodsof the invention.

DETAILED DESCRIPTION OF THE INVENTION

The presently invented compounds that inhibit 5-alpha-reductase have thefollowing Formula (I): ##STR6## in which: Δ¹, Δ⁷, Δ⁸, and Δ¹⁶ are --CH₂--CH₂ -- or --CH═CH--, provided that one of Δ⁷, Δ⁸, and Δ¹⁶ is--CH═CH--;

R₁ is H or C₁₋₈ alkyl;

R₂ is H or C₁₋₈ alkyl;

R₃ is

(1) alpha-hydrogen, alpha-hydroxyl, or acetoxy and

(a) ##STR7## where Alk is absent or present as a straight or branchedhydrocarbon chain of 1 to 12 carbons, and R⁴ is

(i) hydrogen,

(ii) hydroxyl,

(iii) C₁₋₈ alkyl,

(iv) hydroxy C₁₋₈ alkyl,

(v) C₁₋₈ alkoxy,

(vi) NR⁵ R⁶, where R⁵ and R⁶ are each independently selected fromhydrogen, C₁₋₈ straight or branched chain alkyl, C₃₋₆ cycloalkyl,phenyl; or R⁵ and R⁶ taken together with the nitrogen to which they areattached represent a 5-6 membered saturated ring comprising up to oneother heteroatom selected from oxygen and nitrogen, or

(vii) OR⁷, where R⁷ is hydrogen, alkali metal, C₁₋₁₈ straight orbranched chain alkyl, benzyl, or

(b) --Alk--OR⁸, where Alk is always present and has the same meaning asabove, and R⁸ is

(i) phenyl C₁₋₆ alkylcarbonyl,

(ii) C₅₋₁₀ cycloalkylcarbonyl,

(iii) benzoyl,

(iv) C₁₋₈ alkoxycarbonyl,

(v) amino, or C₁₋₈ alkyl substituted amino, carbonyl, or

(vi) hydrogen, provided that Alk is a branched C₃ -C₈ chain,

(2) ═CH--Alk--CO--R⁴ or ═CH--Alk--OR⁸, where Alk is present or absentand has the same meaning as above, and R⁴ and R⁸ have the same meaningas above and R⁸ also is hydrogen or C₁₋₂₀ alkylcarbonyl;

(3) ##STR8## where the dashed bond replaces the 17-alpha-hydrogen, (4)alpha-hydrogen and NHCOR⁹ where R⁹ is C₁₋₁₂ alkyl or NR⁵ R⁶ where R⁵ andR⁶ have the same meaning as above,

(5) alpha-hydrogen and cyano,

(6) alpha-hydrogen and tetrazolyl, or

(7) keto;

or a pharmaceutically acceptable salt thereof.

As used herein C_(1-n) alkyl means a straight or branched hydrocarbonchain having 1 to n carbons.

Preferred among the presently invented compounds are those havingFormula (II): ##STR9## in which: Z is H, alkyl, C₁₋₄ alkoxy, or NR²⁰ R²¹wherein R²⁰ and R²¹ independently are C₁₋₈ alkyl,

Alk is absent or present as a straight or branched hydrocarbon chain of1 to 4 carbons, and

R¹ and R² are as defined in claim 1, or a pharmaceutically acceptablesalt thereof.

Presently, the most preferred compounds of the invention are:

4-methyl-4-aza-5-alpha-8(14)-androsten-3-one-17β-N,N-diisopropylcarboxamide;

4-methyl-4-aza-5-alpha-8(14)-pregnen-3-one-(20R)-20-carboxylic acid; and

(20R)-hydroxymethyl-4-methyl-4-aza-5-alpha-8(14)-pregnen-3-one.

Also preferred among the presently invented compounds are those havingformula (X): ##STR10## in which: Alk is absent or present as a straightor branched hydrocarbon chain of 1 to 4 carbons,

R³⁰ is hydroxy, halo, C₁₋₄ alkoxy, or CO₂ C_(a) H_(2a+1) wherein a is1-5, and

R¹ and R² are as described in Formula (I).

The compounds of Formula (I) wherein Δ or is --CH═CH-- are preparedaccording to either of the equally preferred synthetic pathways shown inSchemes I and II. In Schemes I and II, R¹, R², and R³ are as defined inFormula (I) and R²⁰ is as defined in Formula (II). ##STR11## Accordingto Scheme I, compound A is dissolved in a suitable organic solvent suchas a C₁₋₄ alkyl dihalide in a C₁₋₄ alkanol, preferably methylenechloride in methanol, cooled to approximately -100° C. to 30° C.,preferably -78° C. and treated with ruthenium dioxide/sodium periodate,potassium permanganate, or, preferably, an excess of ozone. Theresulting solution is purged with an inert gas such as argon as it iswarmed to approximately 25° C. to 50° C., preferably 40° C. The solutionthen is concentrated, the carboxylic acid (compound (B)) where R²⁰ ishydrogen is taken up in a suitable organic solvent such asdimethylacetamide, and in the presence of a base such as sodiumbicarbonate or 1,8-diazabicyclo[5.4.0]undec-7-ene (DBU), reacted with aC₁₋₄ alkyl halide such as methylchloride, ethylchloride, methyl bromideor, preferably, methyl iodide to yield a formula (B) compound.Alternatively, the formula (B) compound is prepared by reaction of thecarboxylic acid with diazomethane.

The keto-ester (B) in a suitable organic solvent such as ethyl acetatethen is reacted with phenylselenyl chloride under inert gas such asargon. The resulting solution is cooled to approximately 0° C. to 30°C., preferably 15° C. and treated with an oxidizing agent such as ozone,meta-chloroperbenzoic acid, or, preferably, hydrogen peroxide whilekeeping the temperature below approximately 30° C. to yield a formula Ccompound.

Compounds of formula C then are combined with ammonia or a C₁₋₄alkylamine selected to possess the desired R¹ substituent and heated toapproximately 150° C. to 200° C., preferably 180° C. to prepare formulaD compounds. Formula (I) compounds wherein Δ⁸ is --CH═CH-- then areprepared by standard hydrogenation of formula D compounds usinghydrogenation agents such as platinum dioxide, palladium on carbon,Raney nickel, preferably palladium on carbon and hydrogenation solventssuch as suitable organic solvents. Formula (I) compounds wherein Δ⁷ is--CH═CH-- are prepared by hydrogenation of formula (D) compounds usingRaney nickel and close monitoring of the reaction to minimize or preventformation of Formula (I) compounds wherein Δ⁸ is --CH═CH--.

Preparation of Formula (I) compounds according to Scheme II begins fromthe same starting materials as in Scheme I. Formula N compounds areprepared by reacting Formula A compounds with a quinone oxidant such aschloranil in a suitable organic solvent such as t-butanol. The Formula Ncompounds then are reacted with a nucleophilic thiol compound such asthiophenol, butylmercaptan, or preferably thiolacetic acid to produceformula O compounds.

The thioacetylenone of formula O then is dissolved in a suitable organicsolvent such as a C₁₋₄ alkyldihalide in a C₁₋₄ alkanol, preferablymethylene chloride in methanol, cooled to approximately -100° C. to 0°C., preferably -78° C., and treated with an excess of ozone. Afterpurging with an inert gas such as argon, the solution is concentratedand treated with a strong base such as sodium hydroxide to produce aresidue. The residue then is dissolved in a suitable organic solvent,cooled to approximately -30° C. to 30° C., preferably 0° C. and, in thepresence of a base such as sodium bicarbonate or DBU, treated with aC₁₋₄ alkyl halide such as methylchloride, ethylchloride, methyl iodide,or, preferably, diazomethane to yield a formula P compound.

Compounds of formula P then are combined with ammonia or a C₁₋₄alkylamine selected to possess the desired R¹ substituent and heated toapproximately 150° C. to 200° C., preferably 180° C. to yield formula Qcompounds. Formula (I) compounds then are prepared by hydrogenation offormula P compounds using hydrogenation agents such as palladium oncarbon, or Raney nickel, preferably platinum dioxide, and hydrogenationsolvents such as suitable organic solvents. As in Scheme I, Formula (I)compounds wherein Δ⁷ is --CH═CH-- are prepared by hydrogenation offormula Q compounds using Raney nickel and close monitoring of thereaction to minimize or prevent formation of Formula (I) compoundswherein Δ⁸ is --CH═CH--.

Formula (I) compounds wherein Δ¹ is --CH═CH-- are prepared from Formula(I) compounds synthesized according to Schemes I or II by knownoxidation and elimination reactions as described, for example, inExample 7. Formula (I) compounds wherein Δ¹⁶ is --CH═CH-- are preparedby known dehydrogenation reactions as described, for example, in Example10, from 17-keto Formula I compounds synthesized according to Schemes Ior II.

Compounds of formula A, the starting materials in Schemes I and II, areprepared from the analogous 17-keto compounds by known procedures suchas described in 2 J. Fried and J. Edwards, Organic Reactions in SteroidChemistry, Pub: Van Nostrand Reinhold Company (1972). The 17-ketocompounds are available and can be synthesized by known procedures. Thestarting materials are selected so that the R² and R³ groups in theformula A compound are the same as the R² and R³ groups in the Formula(I) compound being synthesized. Alternatively, the R² and R³ groups ofthe formula A compound are selected so that they can be converted byknown procedures to the R² and R³ groups of the target Formula Icompound by additional steps in the synthetic process. For example,Formula (I) compounds wherein R³ is carboxylic acid are converted to thecorresponding amides by reaction with amines or substituted amines viathe corresponding acid chlorides. Similarly, Formula (I) compoundswherein R³ is CH₃ CHCOOH is prepared by oxidation of the correspondingalcohol.

Pharmaceutically acceptable acid addition salts of the compounds of theinvention are formed where appropriate with strong or moderately strongorganic or inorganic acids in the presence of a basic amine by methodsknown to the art. For example, the base is reacted with an inorganic ororganic acid in an aqueous miscible solvent such as ethanol withisolation of the salt by removing the solvent or in an aqueousimmiscible solvent when the acid is soluble therein, such as ethyl etheror chloroform, with the desired salt separating directly or isolated byremoving the solvent. Exemplary of the acid addition salts which areincluded in this invention are maleate, fumarate, lactate, oxalate,methanesulfonate, ethanesulfonate, benzenesulfonate, tartrate, citrate,hydrochloride, hydrobromide, sulfate, phosphate and nitrate salts.Pharmaceutically acceptable base addition salts of compounds of theinvention prepared by known methods include nontoxic alkali metal andalkaline earth salts, for example, calcium, sodium, and potassium salts;ammonium salts, and salts of nontoxic organic bases such astriethylamine, butylamine, piperazine, and(trihydroxymethyl)methylamine.

In preparing the presently invented compounds of Formula I, novelintermediates of the following Formula III and IV are synthesized.##STR12## in which: R¹ is H or C₁₋₈ alkyl;

R₂ is H or C₁₋₈ alkyl;

R₃ is

(1) alpha-hydrogen, alpha-hydroxyl, or acetoxy and

(a) ##STR13## where Alk is absent or present as a straight or branchedhydrocarbon chain of 1 to 12 carbons, and R⁴ is

(i) hydrogen,

(ii) hydroxyl,

(iii) C₁₋₈ alkyl,

(iv) hydroxy C₁₋₈ alkyl,

(v) C₁₋₈ alkoxy,

(vi) NR⁵ R⁶, where R⁵ and R⁶ are each independently selected fromhydrogen, C₁₋₈ straight or branched chain alkyl, C₃₋₆ cycloalkyl,phenyl; or R⁵ and R⁶ taken together with the nitrogen to which they areattached represent a 5-6 membered saturated ring comprising up to oneother heteroatom selected from oxygen and nitrogen, or

(vii) OR⁷, where R⁷ is hydrogen, alkali metal, C₁₋₁₈ straight orbranched chain alkyl, benzyl, or

(b) --Alk--OR⁸, where Alk is always present and has the same meaning asabove, and R⁸ is

(i) phenyl C₁₋₆ alkylcarbonyl,

(ii) C₅₋₁₀ cycloalkylcarbonyl,

(iii) benzoyl,

(iv) C₁₋₈ alkoxycarbonyl,

(v) amino, or C₁₋₈ alkyl substituted amino, carbonyl, or

(vi) hydrogen, provided that Alk is a branched C₃ -C₈ chain,

(2) ═CH--Alk--CO--R⁴ or ═CH--Alk--OR⁸, where Alk is present or absentand has the same meaning as above, and R⁴ and R⁸ have the same meaningas above and R⁸ also is hydrogen or C₁₋₂₀ alkylcarbonyl;

(3) ##STR14## where the dashed bond replaces the 17-alpha hydrogen, (4)alpha-hydrogen and NHCOR⁹ where R⁹ is C₁₋₁₂ alkyl or NR⁵ R⁶ where R⁵ andR⁶ have the same meaning as above,

(5) alpha-hydrogen and cyano,

(6) alpha-hydrogen and tetrazolyl, or

(7) 17-keto. ##STR15## in which: R₂ is H or C₁₋₈ alkyl;

R₃ is

(1) alpha-hydrogen, alpha-hydroxyl, or acetoxy and

(a) ##STR16## where Alk is absent or present as a straight or branchedhydrocarbon chain of 1 to 12 carbons, and R⁴ is

(i) hydrogen,

(ii) hydroxyl,

(iii) C₁₋₈ alkyl,

(iv) hydroxy C₁₋₈ alkyl,

(v) C₁₋₈ alkoxy,

(vi) NR⁵ R⁶, where R⁵ and R⁶ are each independently selected fromhydrogen, C₁₋₈ straight or branched chain alkyl, C₃₋₆ cycloalkyl,phenyl; or R⁵ and R⁶ taken together with the nitrogen to which they areattached represent a 5-6 membered saturated ring comprising up to oneother heteroatom selected from oxygen and nitrogen, or

(vii) OR⁷, where R⁷ is hydrogen, alkali metal, C₁₋₁₈ straight orbranched chain alkyl, benzyl, or

(b) --Alk--OR⁸, where Alk is always present and has the same meaning asabove, and R⁸ is

(i) phenyl C₁₋₆ alkylcarbonyl,

(ii) C₅₋₁₀ cycloalkylcarbonyl,

(iii) benzoyl,

(iv) C₁₋₈ alkoxycarbonyl,

(v) amino, or C₁₋₈ alkyl substituted amino, carbonyl, or

(vi) hydrogen, provided that Alk is a branched C₃ -C₈ chain,

(2) ═CH--Alk--CO--R⁴ or ═CH--Alk--OR⁸, where Alk is present or absentand has the same meaning as above, and R⁴ and R⁸ have the same meaningas above and R⁸ also is hydrogen or C₁₋₂₀ alkylcarbonyl;

(3) ##STR17## where the dashed bond replaces the 7-alpha hydrogen, (4)alpha-hydrogen and NHCOR⁹ where R⁹ is C₁₋₁₂ alkyl or NR⁵ R⁶ where R⁵ andR⁶ have the same meaning as above,

(5) alpha-hydrogen and cyano,

(6) alpha-hydrogen and tetrazolyl,

(7) 17-keto, and

R²⁰ is C₁₋₈ alkyl.

Because Formula (I) compounds inhibit steroid 5-alpha-reductaseactivity, they have therapeutic utility in treating diseases andconditions wherein decreases in DHT activity produce the desiredtherapeutic effect. Such diseases and conditions include acne vulgaris,seborrhea, female hirsutism, prostate diseases such as benign prostatichypertrophy, and male pattern baldness. The potency of several compoundsof the invention were tested for potency in inhibiting human steroid5-alpha-reductase using tissue from hyperplastic human prostates. Indetermining potency in inhibiting the human enzyme, the followingprocedure was employed:

Frozen human prostates were thawed and minced into small pieces (<5mm³). The tissue was homogenized in 3 to 5 volumes of 20 mM potassiumphosphate, pH 6.5, buffer containing 0.33 M sucrose, 1 mMdithiothreitol, and 50 μM NADPH with a Brinkmann Polytron (SybronCorporation, Westbury, NY). The solution was subjected to sonication for3 to 5 minutes with a Sonifier (Branson Sonic Power Co.) followed byhand homogenization in a glass-to-glass Dounce homogenizer (Kontes GlassCompany, Vineland, NJ).

Prostatic particles were obtained by differential centrifugation at 600or 1000×g for 20 minutes and 140,000×g for 60 minutes at 4° C. Thepellet obtained from the 140,000×g centrifugation was washed with 5 to10 tissue volumes of the buffer described above and recentrifuged at140,000×g. The resulting pellet was suspended in 20 mM potassiumphosphate buffer, pH 6.5, containing 20% glycerol, 1 mM dithiothreitol,and 50 μM NADPH. The suspended particulate solution was stored at -80°C.

A constant amount of [¹⁴ C]-testosterone (52 to 55 mCi/mmol, New EnglandNuclear, Boston, MA) in ethanol and varying amounts of the potentialinhibitor in ethanol were deposited in test tubes and concentrated todryness in a SAVANT Speed Vac. To each tube was added buffer, 20 μl of10 mM NADPH and an aliquot of prostatic particulate solution to a finalvolume of 0.5 ml of 50 mM sodium citrate, pH 5.0. After incubating thesolution at 37° C. for 20 to 30 minutes the reaction was quenched by theaddition of 4 ml ethyl acetate and 0.25 μ mol each of testosterone,dihydrotestosterone, androstanediol, and androstanedione as carriers.The organic layer was removed to a second test tube and evaporated todryness in a Speed Vac. The residue was dissolved in 20 to 30 μlchloroform, spotted on an individual lane of a 20×20 cm prechannelledsilica gel TLC plate (Si 250F-PA, Baker Chemical) and developed twicewith acetone:chloroform (1:9). The radiochemical content in the bands ofthe substrate and the products was determined with a BIOSCAN ImagingScanner (Bioscan, Inc., Washington, DC). The percent of recoveredradiolabel converted to product was calculated, from which enzymeactivity was determined. All incubations were conducted such that nomore than 12% of the substrate (testosterone) was consumed.

The experimentally obtained data was computer fitted to a linearfunction by plotting the reciprocal of the enzyme activity (1/velocity)against the variable inhibitor concentration (Dixon, M. (1953), Biochem.J., 55, 170). Assuming that the steroidal inhibitor is a competitiveinhibitor against testosterone, a value for the inhibition constant(K_(i)) can be calculated from equation 1:

    K.sub.i =(B/A)/S/K.sub.m +1)                               Equation 1

where B is the intercept on the 1/velocity axis, A is the slope of theline, S is the concentration of substrate (testosterone) used in theexperiment, and K_(m) is the Michaelis-Menton constant of the substrate(testosterone) determined in a separate experiment to be 4.5 μM.

                  TABLE II                                                        ______________________________________                                        Inhibition Constants of Human Prostatic Steroid                               5-alpha-Reductase                                                             Compound                    K.sub.i (nM)                                      ______________________________________                                        1)                                                                                  ##STR18##                 450 ± 20                                   2)                                                                                  ##STR19##                 100 ± 10                                   3)                                                                                  ##STR20##                  8 ± 2                                     ______________________________________                                    

Table II displays the results of the above testing and shows that thetested compounds of the invention are potent inhibitors of human steroid5-alpha-reductase.

Certain compounds of the invention also were tested for their in vivopotency in inhibiting steroid 5-alpha-reductase activity. Male CharlesRiver CD rats, 48 days old, weighing approximately 200 gm wereadministered the compounds of the invention shown in Table III dissolvedin propylene glycol and diluted in normal saline. The compounds wereadministered orally at dosages of 5, 10, and 20 mg/kg. Six hoursfollowing compound administration the animals were sacrificed, theventral prostates were excised, and testosterone (T) and DHT levels weremeasured by the following procedure.

Prostate tissue was excised, trimmed, weighed, minced and washed withphosphate buffer. The tissue then was homogenized in phosphate bufferand extracted by addition of ethyl acetate and mixing on an orbitalmixer for forty-five minutes. The ethyl acetate was evaporated, theresidue was reconstituted in ethanol, and was centrifuge filtered using0.45 μM filter paper. The components then were separated usingreverse-phase HPLC collecting T and DHT fractions. The fractions werereduced to dryness and reconstituted in standard T/DHT assay bufferavailable from Amersham. T and DHT levels then were measured usingstandard techniques such as radioimmunoassay.

                  TABLE III                                                       ______________________________________                                        Compound        T*        DHT       T/DHT*                                    ______________________________________                                        Control             0.67 ± .04                                                                           2.08 ± .16                                                                         0.32                                    (20R)-Hydroxy-                                                                            5 mg/kg 0.52 ± .27                                                                           0.72 ± .21                                                                         0.72                                    methyl-4-methyl-                                                                         10 mg/kg 0.44 ± .13                                                                           0.53 ± .12                                                                         0.83                                    4-aza-5-alpha-                                                                           20 mg/kg 0.45 ± .12                                                                           0.49 ± .14                                                                         0.92                                    8(14)-pregnen-3-                                                              one                                                                           4-Methyl-4-aza-                                                                           5 mg/kg 0.34 ± .11                                                                           0.43 ± .12                                                                         0.79                                    5-alpha-8(14)-                                                                           10 mg/kg 0.26 ± .07                                                                           0.34 ± .09                                                                         0.76                                    pregnen-3-one-                                                                           20 mg/kg 0.30 ± .04                                                                           0.34 ± .06                                                                         0.88                                    (20R)-20-car-                                                                 boxylic acid                                                                  ______________________________________                                         *T and DHT levels are given in ng/100 mg ventral prostate tissue ± SEM

In Table III the results obtained in the compound treated animals arecompared to those obtained in vehicle-treated controls. As the datademonstrate, each of the dosage levels tested produced substantialdecreases in prostatic DHT levels thus increasing T/DHT ratios.Therefore, the invented compounds are potent steroid 5-alpha-reductaseinhibitors in vivo.

The time course of in vivo 5-alpha-reductase inhibition produced bycompounds of the invention also was examined. Using procedures similarto those used in generating the data displayed in Table III, rats wereadministered4-methyl-4-aza-8(14)-androsten-3-one-17β-N,N-diisopropylcarboxamide andventral prostate tissue was excised for T and DHT determinations atseveral post-administration time points. As the data in Table IVdemonstrate, when compared to controls, significant differences in DHTlevels were observed at 1, 2, 4, and 8 hours following compoundadministration.

                                      TABLE IV                                    __________________________________________________________________________    Control     1 Hour 2 Hours                                                                              4 Hours                                                                              8 Hours                                      __________________________________________________________________________    T     .436 ± .12                                                                       .533 ± .15                                                                        .481 ± .12                                                                        .607 ± .24                                                                        .565 ± .16                                (ng/100 mg                                                                    tissue)*                                                                      DHT   .754 ± .10                                                                       .532 ± .08**                                                                      .496 ± .05**                                                                      .504 ± .09**                                                                      .498 ± .04**                              (ng/100 mg                                                                    tissue)*                                                                      T/DHT .58   1.00   .97    1.20   1.13                                         __________________________________________________________________________     *Data shown as mean + SEM                                                     **P < .05                                                                

The compounds of Formula I are incorporated into convenient dosage formssuch as capsules, tablets, or injectable preparations. Solid or liquidpharmaceutical carriers are employed. Solid carriers include, starch,lactose, calcium sulfate dihydrate, terra alba, sucrose, talc, gelatin,agar, pectin, acacia, magnesium stearate, and stearic acid. Liquidcarriers include syrup, peanut oil, olive oil, saline, and water.Similarly, the carrier or diluent may include any prolonged releasematerial, such as glyceryl monostearate or glyceryl distearate, alone orwith a wax. The amount of solid carrier varies widely but, preferably,will be from about 25 mg to about 1 g per dosage unit. When a liquidcarrier is used, the preparation will be in the form of a syrup, elixir,emulsion, soft gelatin capsule, sterile injectable liquid such as anampoule, or an aqueous or nonaqueous liquid suspension.

The pharmaceutical preparations are made following conventionaltechniques of a pharmaceutical chemist involving mixing, granulating,and compressing, when necessary, for tablet forms, or mixing, fillingand dissolving the ingredients, as appropriate, to give the desired oralor parenteral products.

Doses of the present compounds of Formula I in a pharmaceutical dosageunit as described above will be an efficacious, nontoxic quantityselected from the range of 0.1-1000 mg/kg of active compound, preferably1-100 mg/kg. The selected dose is administered to a human patient inneed of steroid 5-alpha-reductase inhibition from 1-6 times daily,orally, rectally, by injection, or continuously by infusion. Oral dosageunits for human administration preferably contain from 1 to 500 mg ofactive compound. Parenteral administration, which uses lower dosages ispreferred. Oral administration, at higher dosages, however, also can beused when safe and convenient for the patient.

The method of this invention of inhibiting steroid 5-alpha-reductaseactivity in mammals, including humans, comprises administeringinternally to a subject in need of such inhibition an effective steroid5-alpha-reductase inhibiting amount of a compound of Formula I.

Contemplated equivalents of Formula I compounds are compounds otherwisecorresponding thereto wherein substituents have been added to any of theunsubstituted positions of the Formula I compounds or the methyl groupat C-13 is absent or replaced by C₁₋₄ alkyl provided such compounds havethe pharmaceutical utility of Formula (I) compounds.

The following examples illustrate preparation of Formula I compounds andpharmaceutical compositions containing these compounds. The examples arenot intended to limit the scope of the invention as defined hereinaboveand as claimed below.

EXAMPLE 1 (20R)-Hydroxymethyl-4-methyl-4-aza-5-alpha-8(14)-pregnen-3-one(i) (20R)-20-Hydroxymethyl-4-pregnen-3-one

To a solution of (20R)-3-oxopregn-4-ene-20-carboxaldehyde (100 g, 305mmol, commercially available from Upjohn) in 1500 ml ethanol and 250 mltetrahydrofuran cooled to approximately 5° C. was added sodiumborohydride (3.35 g, 89 mmol) portionwise to keep the temperature below15° C. After 20 minutes, acetic acid (100 ml) was added and the mixturewas concentrated to a slush on a rotary evaporator. The residue was thentaken up in chloroform, successively washed with water and brine, thendried over sodium carbonate and concentrated to yield(20R)-20-hydroxymethyl-4-pregnen-3-one as a white solid (100 g, 100%).

(ii) Methyl (20R)-20-hydroxymethyl-5-oxo-3,5-secopregnan-3-oate

The above enone (100 g, 303 mmol) was dissolved in 1000 mldichloromethane and 500 ml methanol, cooled to -78° C., and treated withan excess of ozone. The resulting solution was purged with argon as itwas warmed to 40° C. The solution was then concentrated to a viscouscolorless oil, taken up in 500 ml dimethylacetamide, and stirred in thedark under argon with 50 g sodium bicarbonate and 50 ml methyl iodidefor 48 hours. The reaction mixture was then poured into 4 μl of coldbrine and extracted with dichloromethane. The organic extracts werethoroughly washed with water and brine then dried over sodium sulfateand concentrated to a yellow-red oil. This oil was filtered through 1000g of silica gel with 25% ethyl acetate in hexane to yield, afterconcentration, the keto ester methyl(20R)-20-hydroxymethyl-5-oxo-3,5-secopregnan-3-oate as a lightly yellowviscous oil (71.8 g, 65%).

(iii) Methyl (20R)-20-hydroxymethyl-5-oxo-3,5-seco-6-pregnen-3-oate

To the keto-ester from above (71.8 g, 197 mmol) in 1500 ml ethyl acetatewas added phenylselenyl chloride (45 g, 235 mmol) and the resulting darksolution was stirred under argon for three hours. The solution was thenwashed with water, saturated sodium bicarbonate, water, brine, and driedover potassium carbonate. The ethyl acetate solution was then cooled to15° C. and treated with 30% hydrogen peroxide (65 ml) keeping thetemperature below 30° C. After 1.5 hours, the solution was washed withwater, saturated sodium carbonate, water, brine, dried and concentratedto a yellow foam (65 g). Column chromatography (silica, 25% ethylacetate in hexane) yielded the ester-enone methyl(20R)-20-hydroxymethyl-5-oxo-3,5-seco-6-pregnen-3-oate as a colorlessviscous oil (3 g, 32%).

(iv) (20R)-Hydroxymethyl-4-methyl-4-aza-5,7-pregnadien-3-one

To the viscous ester-enone from above (1.67 g, 4.6 mmol) was added 10 mlethylene glycol. Methylamine (3.5 g) was then bubbled into the glycolduring which time the ester-enone dissolved. The solution was slowlyheated to 180° C. for 20 minutes before cooling to ambient temperature.The resulting dark solution was diluted with cold water and thoroughlyextracted with chloroform. The combined extracts were washed with water,brine, dried and concentrated to a brown foam (1.74 g) which waschromatographed (silica, 20% ethyl acetate in hexane) to yield dienamide(20R)-hydroxymethyl-4-methyl-4-aza-5,7-pregnadien-3-one as a white solid(380 mg, 24%).

(v) (20R)-Hydroxymethyl-4-methyl-4-aza-5-alpha-8(14)-pregnen-3-one

The dienamide from above (500 mg, 1.38 mmol) in 100 ml ethyl acetatecontaining 1% ethanol was hydrogenated at 25° C. and 1 atm over 1.3 g10% Pd on carbon for 3 hours. The solution was filtered to removecatalyst and concentrated to a white solid. Recrystallization from ethylacetate afforded 300 mg(20R)-hydroxymethyl-4-methyl-4-aza-5-alpha-8(14)-pregnen-3-one as awhite crystalline solid, m.p. (uncorrected) 219°-220° C.

EXAMPLE 2 4-Methyl-4-aza-5-alpha-8(14)-pregnen-3-one-(20R)-20-carboxylicacid

To a solution(20R)-hydroxymethyl-4-methyl-4-aza-5-alpha-8(14)-pregnen-3-one (200 mg,0.56 mmol), prepared in Example 1, in 15 ml acetone and 1 mltetrahydrofuran was added Jones reagent dropwise until a red colorpersisted. Isopropanol was then added to quench the excess oxidant. Thesolution was decanted from the gummy chromium salts, concentrated, andpartioned between dichloromethane and water. The salts were dissolved inwater and extracted with dichloromethane. The combined organic layerswere then washed with brine, dried over sodium sulfate, and concentratedto a white solid. Recrystallization from methanol/ethyl acetate affordedas white crystals4-methyl-4-aza-5-alpha-8(14)-pregnen-3-one-(20R)-20-carboxylic acid (157mg) (112 mg, 54%), m.p. (uncorrected) 310°-315° C.

EXAMPLE 34-Methyl-4-aza-5-alpha-8(14)-androsten-3-one-17β-N,N,-diisopropylcarboxamide(i) Methyl androst-4,6-diene-3-one-17β-carboxylate

Methyl androst-4-ene-3-one-17β-carboxylate (10 g, 30.3 mmol, preparedaccording to Rasmusson, et al., J. Med. Chem. 27 1960 (1984)) andchloranil (8.95 g, 36.4 mmol) in 700 ml t-butanol was heated at refluxfor 3.5 hours then cooled and filtered. The filtrate was concentratedand the residue taken up in 700 ml chloroform and washed successivelywith 4×150 ml water, 3×150 ml saturated sodium bicarbonate, 3×150 ml 5%sodium hydroxide, 3×150 ml brine, dried over sodium sulfate, andconcentrated to yield methyl androst-4,6-diene-3-one-17β-carboxylate asa dark foam (7.0 g, 70%).

(ii) Methyl-6-thioacetyl-androst-4-ene-3-one-17β-carbonate

The dienone from above (7.0 g, 21.3 mmol) and thioacetic acid (15 ml)were heated at reflux for 2.5 hours. Excess thioacetic acid was thenremoved in vacuo and the residue was dissolved in 100 ml ethyl acetateand washed with water, saturated sodium bicarbonate, brine, dried andconcentrated to yield methyl6-thioacetyl-androst-4-ene-3-one-17β-carboxylate as a dark oil (8.46 g,98%).

(iii) Dimethyl 3,5-seco-6-androsten-5-one-3-17β-dicarboxylate

The thioacetyl-enone from above (17.0 g, 42.1 mmol) in 100 mldichloromethane and 50 ml methanol at -78° C. was treated with excessozone. The resulting solution was purged with argon, warmed to ambienttemperature, and concentrated. The residue was dissolved in 100 mlmethanol and 20 ml 10% sodium hydroxide and heated at reflux for 3hours. The solution was then acidified with hydrochloric acid,concentrated, and partitioned between chloroform and water. The aqueouslayer was further extracted with chloroform and the combined organiclayers were washed with brine, dried, and concentrated. The residue wastaken up in diethyl ether with enough dichloromethane to effectdissolution, cooled to 0° C. and treated with an ethereal solution ofexcess diazomethane. Concentration of the resulting solution afforded10.5 g of a yellow oil which was chromatographed (silica, 30% ethylacetate in hexane) to afford compound dimethyl3,5-seco-6-androsten-5-one-3-17β-dicarboxylate (5.0 g, 33%) as acolorless oil.

(iv) Hydroxyethyl 4-methyl-4-aza-5,7-androstadien-3-one-17β-carboxylate

To the enone-ester from above (5.0 g, 13.8 mmol) and 50 ml ethyleneglycol was added methylamine (10 g) after which the enone-ester wasdissolved. The resulting solution was then heated over a 90 minuteperiod to 180° C. and held at that temperature for 20 minutes beforecooling to ambient temperature. The resulting dark solution was dilutedwith cold water and thoroughly extracted with chloroform. The combinedorganic extracts were then washed with water and brine, dried, andconcentrated to a dark brown oil. Chromatography (silica, 1:1 ethylacetate/hexane) afforded dienamide hydroxyethyl4-methyl-4-aza-5,7-androstadien-3-one-17β-carboxylate (1.5 g, 29%) as anoff-white solid.

(v) Hydroxyethyl 4-methyl-4-aza-8(14)-androsten-3-one-17β-carboxylate

The dienamide from above (1.5 g, 4.02 mmol) in 20 ml 10% ethanol inethyl acetate was hydrogenated over 1.5 g palladium dioxide at ambienttemperature and 1 atm. for 3 hours. The catalyst was then removed byfiltration and the solution was concentrated to yield hydroxyethyl4-methyl-4-aza-8(14)-androsten-3-one-17β-carboxylate as a white solid(1.5 g).

(vi) 4-Methyl-4-aza-8(14)-androsten-3-one-17β-carboxylic acid

The hydroxyethyl ester from above (1.5 g, 4.0 mmol) and potassiumcarbonate (3 g) in 150 ml 10:1 methanol-water was heated at reflux for12 hours. The resulting mixture was concentrated, diluted with water,acidfied, and thoroughly extracted with chloroform. The chloroform wasevaporated and the residue was chromatographed (silica, 5% methanol indichloromethane) to yield4-methyl-4-aza-8(14)-androsten-3-one-17β-carboxylic acid (0.75 g, 57%)as a white solid.

(vii) 4-Methyl-4-aza-8(14)-androsten-3-one-17β-carboxylic acid chloride

A solution of the acid from above (250 mg, 0.75 mmol) in toluene (8 ml)was treated with 0.5 ml oxalyl chloride. After 2 hours the volatilematerials were removed at 1 mmHg leaving a residue of4-methyl-4-aza-8(14)-androsten-3-one-carboxylic acid chloride.

(viii)4-Methyl-4-aza-5-alpha-8(14)-androsten-3-one-17β-N,N-diisopropylcarboxamide

A solution of the above acid chloride (283 mg, 0.75 mmol) in 8 mltetrahydrofuran was treated with 1 ml diisopropylamine overnight. Thesolution was diluted with water and extracted thoroughly withdichloromethane. The extracts were dried and concentrated to a whitesolid. Preparative HPLC (silica, 10% isopropyl alcohol in hexane)followed by recrystallization from diethyl ether afforded4-methyl-4-aza-5-alpha-8(14)-androsten-3-one-17β-N,N-diisopropylcarboxamide(100 mg), m.p. (uncorrected) 185°-190° C.

EXAMPLE 4 4-Methyl-4-aza-8(14)-androsten-3-one-17β-carboxaldehyde

A solution of 4-methyl-4-aza-8(14)-androsten-3-one-17β-carboxylchlicacid chloride (378 mg, 1 mmol), prepared as in Example 3, in 10 mltetrahydrofuran is treated with lithium tri-t-butoxyaluminum hydride(254 mg, 1 mmol) at 0° C. for one hour to yield, after aqueous workup,4-methyl-4-aza-8(14)-androsten-3-one-17β-carboxaldehyde.

EXAMPLE 5 4-Methyl-4-aza-17β-(1-oxobutyl)-8(14)-androstene-3-one

A solution of 4-methyl-4-aza-8(14)-androsten-3-one-17β-carboxylic acidchloride (378 mg, 1 mmol) in 10 ml tetrahydrofuran is treated withdi-n-butyl copperlithium at -78° C. The reaction is quenched withaqueous ammonium chloride. Extraction with dichloromethane followed byconcentration of the organic extract yields4-methyl-4-aza-17β-(1-oxobutyl)-8(14)-androstene-3-one.

EXAMPLE 6 (20R)-Hydroxymethyl-4-methyl-4-aza-5-alpha-7-pregnen-3-one

Active Raney nickel W-2 catalyst (500 mg) which had been washed withwater, ethanol, and ethyl acetate, was suspended in a solution of(20R-hydroxymethyl-4-methyl-4-aza-5,7-pregnadien-3-one (115 mg, 0.33mmol), prepared as in Example 1, in 15 ml ethyl acetate and stirredunder 1 atm. of hydrogen for twenty hours. The catalyst was then removedby filtration and the filtrate was concentrated to a white solid.Chromatography (silica, 6:3:1 cyclohexane-acetone-ethyl acetate)afforded 56 mg of the starting material,(20R)-hydroxymethyl-4-methyl-4-aza-5,7-pregnadien-3-one, and 46 mg of(20R)-hydroxymethyl-4-methyl-4-aza-5-alpha-7-pregnen-3-one as whiteneedles (recrystallized from ethyl acetate), m.p. 196°-199° C.

EXAMPLE 74-Methyl-4-aza-5-alpha-1,8(14)-androstadien-3-one-17β-N,N-diisopropylcarboxamide

A solution of4-methyl-4-aza-8(14)-androsten-3-one-17β-N,N-diisopropylcarboxamide (345mg, 1 mmol) in 5 ml tetrahydrofuran at -70° C. is treated with asolution of lithium diisopropylamide in hexane-pentane (2 ml of 1.5 M, 3mmol) and allowed to warm to 0° C. This solution is then added to asolution of diphenyl disulfide (300 mg, 1.38 mmol) in 2 mltetrahydrofuran and then allowed to stand for 2 hours at roomtemperature. The mixture is then partitioned between water and ethylacetate. The organic layer is washed with dilute sodium hydroxide,water, dilute hydrochloric acid, water and brine and concentrated to aresidue. The residue is dissolved in 10 ml methanol and treated at 0° C.with an aqueous solution of sodium periodate (400 mg., 1.87 mmol, 2 mlwater) for 2.5 hours. The mixture is diluted with water and precipitateis filtered and dried. The precipitate is dissolved in toluene, heatedat reflux for 3 hours and then concentrated. Recrystallization fromethyl acetate affords4-methyl-4-aza-5-alpha-1,8(14)-androstadien-3-one-17β-N,N-diisopropylcarboxamide.

EXAMPLE 8 4-Methyl-4-aza-5-alpha-8(14)-androsten-3-one-17β-ol

The title compound is prepared according to Example 1 by replacingtestosterone for (20R)-3-oxopregn-4-ene-20-carboxaldehyde.

EXAMPLE 9 4-Methyl-4-aza-5-alpha-8(14)-androsten-3,17-dione

A solution of 4-methyl-4-aza-8(14)-androsten-3-one-17β-ol (301 mg, 1mmol), prepared as in Example 8, in 10 ml acetone is treated with JonesReagent until a red color persists. Excess reagent is quenched byaddition of isopropanol. The solution is decanted from the thick, greenchromium salts and the salts are then dissolved in water and extractedwith dichloromethane. The combined organic layers are filtered through abed of magnesium sulfate and concentrated to yield4-methyl-4-aza-5-alpha-8(14)-androsten-3,17-dione.

EXAMPLE 10 Ethyl4-methyl-3-oxo-4-aza-5-alpha-pregn-8(14)-17(20)-dien-21-oate

A solution of sodium ethoxide (2.8 g, 41 mmol) in 15 ml ethanol is addedto a mixture of 4-methyl-4-aza-5-alpha-8(14)-androsten-3,17-dione (4.0g, 13.3 mmol), prepared as in Example 9, and methyldiethylphosphonoaetate (8.7 g, 41 mmol) and the resulting mixture heatedat reflux for 4 hours. The mixture is cooled, concentrated, diluted withdilute aqueous acetic acid and extracted with ether. The combinedethereal extracts are washed with water, saturated aqueous sodiumbicarbonate, brine, and concentrated to yield ethyl4-methyl-3-oxo-4-aza-5-alpha-pregn-8(14)-17(20)-dien-21-oate.

EXAMPLE 114-Methyl-4-aza-5-alpha-8(14),16-androstadien-3-one-17-trifluoromethylsulfonate

A solution of 4-methyl-4-5-alpha-8(14)-androsten-3,17-dione (3 g, 10mmol), prepared as in Example 9, trifluoromethylsulfonic anhydride (3.8g, 15 mmol), and 2,6-di-t-butyl-4-methyl-pyridine (2.6 g, 12.5 mmol) in100 ml dichloromethane is stirred at room temperature for 4 hours. Theresulting solution is concentrated. The residue is taken up in ethylacetate-pentane, filtered, and washed with dilute HCl, aqueous sodiumbicarbonate, brine, and then concentrated. Chromatography (silica, 7:3ethyl acetate-hexane) yields4-methyl-4-aza-5-alpha-8(14),16-androstadien-3-one-17-trifluoromethylsulfonate.

EXAMPLE 12 Methyl4-methyl-4-aza-5-alpha-8(14),16-androstadien-3-one-17-carboxylate

A mixture of4-methyl-4-aza-5-alpha-8(14),16-androstadien-3-one-17-trifluoromethylsulfonate(436 mg, 1 mmol), prepared as in Example 11, triethylamine (200 mg, 2mmol), methanol (1.8 ml, 40 mmol), and bis(triphenylphosphine)palladium(II) acetate (22 mg, 0.03 mmol) in 4 ml dimethylformamide is stirredunder an atmosphere of carbon monoxide for 4 hours. The mixture is thendiluted with water and extracted with methylene chloride. The methylenechloride solution is concentrated and the residue chromatographed(silica, 5% methylene chloride) to yield methyl4-methyl-4-aza-5-alpha-8(14),16-androstadien-3-one-17-carboxylate.

EXAMPLE 134-Methyl-4-aza-5-alpha-8(14),16-androstadien-one-17-carboxylic acid

4-Methyl-4-aza-5-alpha-8(14),16-androstadien-one-17-carboxylic acid isprepared according to the procedure of Example 3 (iv) replacinghydroxyethyl 4-methyl-4-aza-8(14)-androsten-3-one-17β-carboxylate withmethyl 4-methyl-4-aza-5-alpha-8(14)-androstadien-3-one-17 -carboxylate.

EXAMPLE 144-Methyl-4-aza-5-alpha-8(14),16-androstadien-3-one-17-N,N-diisopropylcarboxamide

4-methyl-4-aza-5-alpha-8(14),16-androstadien-3-one-17-N,N-diisopropylcarboxamideis prepared according to the procedure of Example 3 (vii) by replacing4-methyl-4-aza-8(14)-androsten-3-one-17β-carboxylic acid with4-methyl-4-aza-5-alpha-8(14),16-androstadien-3-one-17β-carboxylic acid.

EXAMPLE 15N,N-Diisopropyl-4-methyl-3-oxo-4-aza-5-alpha-pregen-8(14),17(20)-dien-21-amide

N,N-Diisopropyl-4-methyl-3-oxo-4-aza-5-alpha-pregen-8(14),17(20)-dien-21-amideis prepared according to the procedure of Example 3 (vii) by replacing4-methyl-4-aza-8(14)-androsten-3-one-17β-carboxylic acid with4-methyl-3-oxo-4-aza-5-alpha-pregen-8(14), 17(20)-dien-21-carboxylicacid.

EXAMPLE 162'3'alpha-Tetrahydrofuran-2'-spiro-17-(4-methyl-4-aza-8(14)-androsten-3-one

The process of Example 1 beginning with2',3'alpha-tetrahydrofuran-2'-spiro-17-(4-androsten-3-one) yields2'3'alpha-tetrahydrofuran-2'-spiro17-(4-methyl-4-aza-8(14)-androsten-3-one

EXAMPLE 17 17β-Acetamido-4-methyl-4-aza-8(14)-androsten-3-one

The process of Example 1 beginning with 17β-acetamido-4-androsten-3-oneyields 17β-acetamido-4-methyl-4-aza-8(14)-androsten-3-one.

EXAMPLE 1817-Carbomethoxy-4-methyl-4-aza-5alpha-8(14)-androstene-3-one-17-ol

4-Methyl-4-aza-5-alpha-8(14)-androstene-3,17-dione (303 mg) is dissolvedby gentle warming in 0.5 ml of freshly prepared acetone cyanohydrin.After two hours at room temperature the precipitated solid is collectedto afford the cyanohydrins as a mixture of epimers at C-17. The mixtureis dissolved in a solution of pyridine (1 ml) and acetic anhydride (1ml) and allowed to stand at room temperature for 48 hours. Removal ofthe solvents under reduced pressure affords an oil which is dissolved inether and washed with 1n hydrochloric acid followed by aqueous sodiumbicarbonate. The organic solution is dried and concentrated to affordthe cyanohydrin acetates as a mixture of epimers at C-17.

The mixture of cyanohydrin acetates is dissolved in anhydrous methanoland cooled to 15 degrees. Dry hydrochloric acid is bubbled in and themixture allowed to stand at room temperature for 2 hours. Solvent isthen removed under reduced pressure. A mixture of tetrahydrofuran (2 ml)and water (w ml) is added followed by sodium hydroxide pellets (1 g) andthe mixture is stirred for 2 hours at room temperature, then acidifiedand extracted with dichloromethane. The mixture of hydroxyacids which isobtained on concentration is dissolved in ether and treated withdiazomethane to afford the hydroxy methyl esters. Chromatography onsilica gel affords17β-carbomethoxy-4-methyl-4-aza-5-alpha-8(14)-androstene-3-one-17-ol.

EXAMPLE 1917β-(5)Tetrazololyl-4-methyl-4-aza-5-alpha-8(14)-androstene-3-one

17-Carbomethoxy-4-methyl-4-aza-5-alpha-8(14)-androstene-3-one (303 mg),prepared as in Example 18, in tetrahydrofuran (5 ml) at -78° C. istreated slowly with Redal (0.5 mmol) and the solution maintained at -78°C. for 2 hours then treated with aqueous ammonium chloride. The mixtureis extracted with ether, the organic solution washed with brine, driedand concentrated to afford17-carboxyaldehyde-4-methyl-4-aza-5-alpha-8(14)-androstene-3-one.

This is then dissolved in pyridine (0.5 ml) and treated withhydroxylamine hydrochloride (80 mg) at room temperature overnight. Themixture is diluted with ether, and washed with water and brine thendried and evaporated to afford the oxime of17-carboxaldehyde-4-methyl-4-aza-5-alpha-8(14)-androstene-3-one.

This was dissolved in dichloromethane (2 ml) and treated with1,1'-carbonyldiimidazole (165 mg). After 1 hour at room temperature thesolution was diluted with dichloromethane and washed with water, thenbrine, then dried and concentrated to afford17-carbonitrile-4-methyl-4-aza-5-alpha-8(14)-androstene-3-one.

This was dissolved in dimethylforamide (2 ml) and treated with sodiumazide (55 mg), lithium chloride (50 mg) and benzylamine hydrochloride(10 mg). The mixture was then heated at 110° C. for 24 hours. Oncooling, the solution was diluted with water and in hydrochloric acid (1ml) and the precipitated tetrazole filtered off and dried.

EXAMPLE 20

An oral dosage form for administering the presently invented compoundsis produced by screening, mixing, and filling into hard gelatin capsulesthe ingredients in the proportions shown in Table V, below.

                  TABLE V                                                         ______________________________________                                        Ingredients             Amounts                                               ______________________________________                                        4-Methyl-4-aza-5-alpha-8(14)-androsten-3-                                                             50 mg                                                 one-17β-N,N-diisopropylcarboxamide                                       magnesium stearate       5 mg                                                 lactose                 75 mg                                                 ______________________________________                                    

EXAMPLE 21

The sucrose, calcium sulfate dihydrate and4-aza-5-alpha-8(14)-17-substituted-androsten-3-one shown in Table VIbelow, are mixed and granulated in the proportions shown with a 10%gelatin solution. The wet granules are screened, dried, mixed with thestarch, talc and stearic acid, screened and compressed into a tablet.

                  TABLE VI                                                        ______________________________________                                        Ingredients            Amounts                                                ______________________________________                                        4-Methyl-4-aza-5-alpha-8(14)-androsten-                                                              100 mg                                                 3-one-17β-N,N-diisopropylcarboxamide                                     calcium sulfate dihydrate                                                                            150 mg                                                 sucrose                 20 mg                                                 starch                  10 mg                                                 talc                    5 mg                                                  stearic acid            3 mg                                                  ______________________________________                                    

EXAMPLE 22

4-Methyl-3-oxo-4-aza-5-alpha-pregn-8(14),17(20)-dien-21-carboxylic acid,75 mg, is dispursed in 25 ml of normal saline to prepare an injectablepreparation.

While the preferred embodiments of the invention are illustrated by theabove, it is to be understood that the invention is not limited to theprecise instructions herein disclosed and that the right to allmodifications coming within the scope of the following claims isreserved.

What is claimed is:
 1. A compound of the formula ##STR21## in which: R₂is H or C₁₋₈ alkyl;R₃ is(1) alpha-hydrogen, alpha-hydroxyl, oralpha-acetoxy and(a) ##STR22## where Alk is absent or present as astraight or branched hydrocarbon chain of 1 to 12 carbons, and R⁴ is(i)hydrogen, (ii) hydroxyl, (iii) C₁₋₈ alkyl, (iv) hydroxy C₁₋₈ alkyl, (v)NR⁵ R⁶, where R⁵ and R⁶ are each independently selected from hydrogen,C₁₋₈ straight or branched chain alkyl, C₃₋₆ cycloalkyl, phenyl; or R⁵and R⁶ taken together with the nitrogen to which they are attachedrepresent a 5-6 membered saturated ring comprising up to one otherheteroatom selected from oxygen and nitrogen, or (vi) OR⁷, where R⁷ isalkali metal, C₁₋₁₈ straight or branched chain alkyl, benzyl, or (b)--Alk--OR⁸, where Alk is always present and has the same meaning asabove, and R⁸ is(i) phenyl C₁₋₆ alkylcarbonyl, (ii) C₅₋₁₀cycloalkylcarbonyl, (iii) benzoyl (iv) C₁₋₈ alkoxycarbonyl, (v) amino,or C₁₋₈ alkyl substituted amino, carbonyl, or (vi) hydrogen, providedthat Alk is a branched C₃ -C₈ chain, (2) ═CH--Alk--CO--R⁴ or═CH--Alk--OR⁸, where Alk is present or absent and has the same meaningas above, and R⁴ and R⁸ have the same meaning as above and R⁸ also ishydrogen or C₁₋₂₀ alkylcarbonyl; (3) ##STR23## where the dashed bondreplaces the 17-alpha-hydrogen, (4) alpha-hydrogen and NHCOR⁹ where R⁹is C₁₋₁₂ alkyl or NR⁵ R⁶ where R⁵ and R⁶ have the same meaning as above,(5) alpha-hydrogen and cyano, (6) alpha-hydrogen and tetrazolyl; or (7)keto; and R²⁰ is C₁₋₁₈ alkyl.
 2. The compound of claim 1 that ismethyl-(20R)-20-hydroxymethyl-5-oxo-3,5-seco-6-pregnenoic acid.
 3. Thecompound of claim 1 that is dimethyl-3,5-seco-6-androsten-5-one-3oicacid-17β-carboxylate.